1. Field
The present disclosure relates to a method and a system for performing color registration on template media having template markings thereon by taking both light scatter from test pattern and light absorption by the test pattern into account.
2. Description of Related Art
In a continuous feed direct marking printer, e.g., based on solid inkjet technology, multiple printheads are distributed over a long print zone to obtain the desired color and image resolutions. Image Registration and Color Control (IRCC) technology is configured to achieve color to color registration using a closed feedback loop controller. At cycle up of the continuous feed direct marking printer, the closed feedback loop controller is configured to print a registration control target (i.e., test pattern), capture the registration control target using a linear array sensor, analyze the linear array sensor response profile, and determine the x-position and y-position of each printhead. The computed registration errors are corrected by y-registration actuators and x-registration actuators. This IRCC technology has been demonstrated in the continuous feed direct marking printer for a blank paper.
The transaction printing industry uses pre-printed forms. For example, these pre-printed forms are used as medical claim forms, shipping documents, purchase orders, insurance records, etc. These pre-printed forms are used, for example, to add color, logos, etc. to a large market mainly populated by monochrome (i.e., one color or shades of one color) web printers.
The pre-printed rolls are produced using offset technology. In offset technology, inked image is transferred or “offset” from a plate to an intermediate surface (e.g., rubber blanket), and then to the printing surface.
Full color digital web printers with the capability to produce excellent graphics are now being offered. The transition from preprinted forms to execute the entire print job in one machine may take some time, because the transition requires not only substituting monochrome printers but also, for example, changing the workflow, etc.
The use of preprinted forms (or offset “shells”) presents a problem for the registration strategy of the continuous feed direct marking printer. That is, setup test pattern (such as color registration test target) that is printed on top of the pre-printed form is confounded with the pre-printed form. This issue (i.e., the registration control target is confounded with the pre-printed form) precludes the actual analysis of the x- and y-positions of the printheads. Further, it is not practical to print the test patterns on blank paper since that would require swapping out the web roll.
The present disclosure provides improvements in registration strategy of preprinted forms.